1. Field of the Invention
The present invention relates to an automatic-locking damping or shock absorber unit principally designed to prevent damage to pipelines in thermonuclear power stations in the event of an earthquake.
2. Description of the Prior Art
Oil pressure damping units which are pivotably mounted, both on supports rigidly attached to a stationary wall and also on the pipe system or pipeline to be protected, are already available.
These damping units are internally equipped with a preregulated automatic locking device which exerts a sufficiently powerful locking action to prevent the pipes or pipeline from commencing to resonate. They produce a stationary point and prevent the breakage or damage caused by seismic shocks, by battering, by the violent shocks and blows resulting from the sudden release of safety valves or from pipeline breaks.
The automatic locking device only operates in the event of sudden movements and, since the damping or shock absorbing unit is equally well suited to withstand pulling forces as compression forces, it does not present any resistance to slow movements such as those resulting from expansion.
The sturdy nature of these units, their sensitivity and minimal response time render them capable of efficiently withstanding virtually any test.
These qualities must be retained in humid, chemically charged and radiation prone environments found in nuclear power stations.
The Applicant has been able to obviate the different disadvantages resulting from secondary effects such as pollution of the oil in contact with the atmosphere, cavitation phenomena and radiation resistance and also to compensate for volume variations resulting from expansion of the oil following an increase in temperature by means of a unit comprising metal diaphragms or capsules disposed in series.